1. Field of the Invention
The present invention relates to vehicles that are propelled using a source of compressed gas, such as air, and more particularly, to a system and method for improving the efficiency of such vehicles by use of one or more Magnus rotors that reduce the weight of the vehicle and while facilitating compression of gas to charge the compressed air tank.
2. Description of Related Art
It is known in the art to use compressed gas as a working fluid to drive an engine. This concept has been successfully used to propel a vehicle. So called compressed air cars used motors powered by compressed air. Such cars can be powered solely by air, or incorporate hybrid propulsion technology.
Compressed air cars are powered by motors fueled with compressed air which is stored in a tank at high pressure. Expansion of the compressed air drives the pistons, in a similar manner to the expansion of steam in a steam engine. Compressed air vehicles offer a number of advantages including: (1) the ability to be refueled using a simple air compressor; (2) compressed air engines can be manufactured cost effectively as they do not require cooling systems, spark plugs, mufflers etc.; (3) the expansion of the compressed air lowers its temperature such that it may be used as air conditioning; (4) compressed air engines significantly eliminate the use of hazardous chemicals such as gasoline, and battery acids; and (5) some compressed air vehicles are adapted to recover braking energy for use in compressing and storing air.
While compressed air vehicles provide a number of advantages over their internal combustion engine counterparts, large scale manufacture of compressed air vehicles has been slow to materialize. Various manufacturers are, however, currently investing in the research and development of compressed air cars. Indian manufacturer Tata Motors is planning a limited production run of compressed air vehicles for use in India and a few other countries. It is expected that the top-speed for this vehicle will be 68 mph with a range of 125 miles. The tanks containing the compressed air can be refilled at special stations, or using the on-board electric compressor in 3-4 hours. Moteur Development International (MDI), the French manufacturer of compressed air vehicles, and Zero Pollution Motors (ZPM) are planning a larger vehicle for the U.S. market in 2010. That car is rumored to have a range of 1000 miles utilizing a dual energy source.
As should be apparent, the art of compressed air vehicles is in its infancy, and there exists a need for advancements in the art to allow for the manufacture of compressed air vehicles.